Salmon Purse Seine Exploitation Rates

Discussion in 'Fly Fishing Forum' started by MaxLedbetter, Nov 12, 2001.

  1. MaxLedbetter New Member

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    I am waiting for replies from the National Library of Canada and other agencies regarding the microform, paper, and/or electronic distribution of my dissertation (Ledbetter, Max. 1986. Competition and information among British Columbia salmon purse seiners. Ph.D. Thesis. University of British Columbia). Here is the abstract:


    In British Columbia, salmon purse seiners line up at fishing access points, forming well defined queues. These queues were measured over time in Johnstone Strait using a one dimensional recording scale. Sixty-one overflights of the fishing area were attempted; 51 flights were completed.

    Two models were presented for exploitation rates in relation to queuing patterns. The overflight model was based upon the line-up
    distributions and assumed that information was good. The model fit well and the parameter estimates reflected anecdotal and statistical information about fish behavior. The exploitation rates saturated at an effort level of 100 vessels (whereas the maximum effort observed was 363 boats) and indicated that (at saturation) the fleet caught 80% to 90% of the vulnerable salmon.

    In general, traditional assumptions were rejected. Vessels did not operate independently. Boats were not distributed in a random fashion. The overflight model provided predicted exploitation rates. The exploitation response to effort was qualitatively distinct from the forms incorporated in traditional models.

    http://www.thefishfinder.com/members/saltwater/ledbetter/

    http://www.thefishfinder.com/members/saltwater/ledbetter/boat0006.JPG

    e-mail: ledbetter@bungo.com